Trees can be harvested and used for building material and/or fuel, and can be processed for paper and/or cardboard among various other wood based products. It can be desirable or required to plant new trees to replace harvested trees to replenish and maintain forests.
Many hybrid trees can be reproduced from cuttings (“slips”) taken from existing trees. These cuttings or slips are often available from nurseries in the form of sticks having a plurality of bud sites thereon. The sticks can come in various lengths and diameters depending upon the type of tree and cultural practices in the local area.
Manually planting the slips by spading or driving them into the ground by hand at desired locations can be slow, highly labor-intensive and generally costly. The slips can require careful planting placement at predetermined intervals and at a proper predetermined depth.
Mechanized planting has been attempted, but the early prototype tree planting machines had circular shaped stick drivers with a tangentially mounted hammer head that struck the slips in an essentially arcuate motion to drive them into the ground as the planter moved. This tended to damage the slips and often left the planted slip leaning at an undesirable angle with respect to vertical. Furthermore, the ground speed of such tree planting machines had to be matched closely to the rotational speed of the driver, thus limiting the speed of planting.
One mechanized planting device plants trees vertically by employing brakes and a pivoting mechanism to temporarily halt movement of a portion of the planter with respect to the frame to maintain a driving plunger horizontally stationary with respect to the ground while the frame is pulled across the ground. In such a planting device, the plunger arm of a hydraulic cylinder can be deployed downward to drivingly engage the tree slips into the ground. When using a hydraulic plunger arm to push the slips into the ground, the rate at which the slips are driven downward can be limited to the rate of the plunger arm itself. This can limit the slip planting rate (e.g., the number of slips planted per time), and can employ large amounts of hydraulic power in order to drive the plunger arm downward to a sufficient speed. The rate at which such devices drive the slips can often require preparing the ground soil prior to planting slips, e.g., by using a coulter or other planting preparation means, in order to plant the slips to an appropriate depth.
Such planting devices can also decrease the slip planting rate by limiting the speed at which the planting device frame and/or driving plunger can be moved across the ground in a planting direction, as the pivoting mechanism expands and retracts each time a slip is to be planted. Such planting devices can also be insufficient for planting slips in areas having terrain conditions that are hard, rocky, or dry, among other conditions.